1. Field of the Invention
The present invention relates to an ellipsometer, more particularly, to an ellipsometer combined with an integrating sphere to measure film thickness, material complex refractive indices, micro root-mean-square surface roughness, surface particulates, bulk particulates, micropollutants, and sub-surface defects of testpieces through multiple incident angles.
2. Description of Related Art
Quality monitoring and control of film thickness, material complex refractive indices, micro root-mean-square roughness, surface particulates, bulk particulates micropollutants, and sub-surface defects are very important issues for semiconductor fabrication, liquid crystal display manufacturing, film coating and disk drive manufacturing. In the semiconductor or disk drive fabricating process, measuring film thickness is effected by utilizing an ellipsometer, while detecting surface conditions is effected by utilizing a microscope. Alternatively, other contacting or non-contacting measuring methods can also be used. However, identifying defects requires utilizing special purpose instruments specifically to detect the defect. In addition, the surface evenness of a semiconductor wafer can only be measured by selectively detecting on the wafer itself.
As high-density integrated circuits such as 256M DRAM are developed, even very small defects (e.g. 20 nm) may cause current leakage and degradation in the quality of the film. As such, it is essential to improve the instruments used in measuring the thickness and quality of the film.